Publications by authors named "Changhyeong Lee"

The role of body composition parameters in sorafenib-treated hepatocellular carcinoma (HCC) patients is still not fully elucidated. Here, we aimed to evaluate the impact of computed tomography (CT)-based body composition parameters on the survival of such patients. In this multicenter study, we analyzed the data of 245 sorafenib-treated HCC patients from January 2008 to December 2019.

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An ultra-wideband electromagnetic (EM) absorber is proposed. The proposed absorber consists of two thin metasurfaces, four dielectric layers, a glass fiber reinforced polymer (GFRP), and a carbon fiber reinforced polymer (CFRP) which works as a conductive reflector. The thin metasurfaces are accomplished with 1-bit pixelated patterns and optimized by a genetic algorithm.

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Purpose: Tenofovir disoproxil (TD), modified from tenofovir disoproxil fumarate (TDF), was developed as a salt-free formulation, removing fumarate to improve the ease of oral intake by reducing the tablet's size. We evaluated the maintenance of antiviral effects and overall safety profile of TD 245 mg after switching from TDF 300 mg in patients with chronic hepatitis B (CHB).

Patients And Methods: CHB patients with HBV-DNA <69 IU/mL after ≥24 weeks of TDF therapy were enrolled.

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Background: Tenofovir disoproxil fumarate (TDF, Viread) had been used as a standard treatment option of chronic hepatitis B (CHB). This clinical trial was conducted to evaluate the efficacy and safety of DA-2802 (tenofovir disoproxil orotate) compared to TDF.

Methods: The present study was a double blind randomized controlled trial.

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In this paper, an intuitive approach to assessing advantages of beamforming in 5G wireless communication is proposed as a novel try and practical demonstration of importance of alignment between the transmitter's and receiver's beams working in millimeter-wave frequency bands. Since the diffraction loss of millimeter-wave signals matters seriously in propagation, the effects of the misalignment and alignment between beams need to be checked for, which was conducted with a horn antenna and the 4 × 4 Butler matrix which mimic the relationship of the base station and handset antennas. Designing and using the microstrip-line and the substrate integrated waveguide (SIW) Butler matrices, RF-to-RF wireless connectivity between the horn and the microstrip line beamformer as case 1 and the horn and the SIW beamformer as case 2, concerning the changing angle of the beam from either of the two Butler matrices, was tested, showing over 12 dB enhancement in received power.

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In this paper, a new sensor is developed to estimate the dielectric constant of Cyclo Olefin Polymer (COP) film utilizable for 5G mobile phones' multi-layered back-cover. It is featured by the electrical characterization of the thin layer of the COP film at 28 GHz as the material under test (MUT) directly contacting the planar probe (which is an array of resonating patches) and a new meta-surface as metal patterned on the COP film inserted between the planar probe and the 5G multi-layered back-cover for enhanced physical interpretation of the data by way of impedance matching. In this approach to delving into the material, a thin and small meta-surface film with an area of 25.

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Objective: The reliable risk factors for mortality of COVID-19 has not evaluated in well-characterised cohort. This study aimed to identify risk factors for in-hospital mortality within 56 days in patients with severe infection of COVID-19.

Design: Retrospective multicentre cohort study.

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Background/aims: Although coronavirus disease 2019 (COVID-19) has spread rapidly worldwide, the implication of pre-existing liver disease on the outcome of COVID-19 remains unresolved.
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Methods: A total of 1,005 patients who were admitted to five tertiary hospitals in South Korea with laboratory-confirmed COVID-19 were included in this study.

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In this paper, a new design method is proposed for a planar and compact dual-band dipole antenna. The dipole antenna has arms as a hybrid CRLH (Composite right- and left-handed) transmission-line comprising distributed and lumped elements for the dual-band function. The two arms are fed by the outputs of a compact and printed CRLH dual-band balun which consists of a CRLH hybrid coupler and an additional CRLH phase-shifter.

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In this paper, a new small antenna is suggested for 5G Sub-6-GHz band mobile communication. It can change the channel among the three given bands (called the 3.5-GHz area), as a wide-band antenna is connected to a small multiplexer comprising three metamaterial channel filters.

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Background & Aims: Treatment of chronic hepatitis B virus (HBV) infection with entecavir suppresses virus replication and reduces disease progression, but could require life-long therapy. To investigate clinical outcome events and safety associated with long-term treatment with entecavir, we followed up patients treated with entecavir or another standard-of-care HBV nucleos(t)ide analogue for up to 10 years. We assessed long-term outcomes and relationships with virologic response.

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Unlabelled: Bone marrow-derived mesenchymal stem cell (BM-MSC) transplantation has been suggested as an effective therapy for liver cirrhosis. The efficacy and safety of autologous BM-MSC transplantation in the treatment of alcoholic cirrhosis were investigated. Seventy-two patients with baseline biopsy-proven alcoholic cirrhosis who had been alcohol-abstinent for more than 6 months underwent a multicenter, randomized, open-label, phase 2 trial.

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Background And Aim: Livers from lipopolysaccharide-treated rats have a decreased vascular response to alpha(1)-adrenergic agonists due to an increased production of nitric oxide. Kupffer cells play a central role in the development of intrahepatic microvascular abnormalities during endotoxemia. We investigated the role of Kupffer cells in the intrahepatic vascular tone control in normal and endotoxemic rats.

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